When Your Autistic Young Adult Refuses to Engage: How to Support the Whole Family Without Losing Yourself

Managing PDA, RSD, substance use, and family tension when your adult child won’t leave home

Raising a neurodivergent child doesn’t stop when they turn 18. In fact, for many families, the most complex parenting begins during young adulthood. When your autistic child is old enough to be legally independent but emotionally unequipped to leave home—and when you’re dealing with refusal to engage, stonewalling, explosive emotional reactions, or substance use—the stress can feel unrelenting.

Add to that dynamic a mother with ADHD (often with her own regulation challenges), a father who feels the young adult’s behaviour is abusive or manipulative, and younger siblings being impacted—and you have a recipe for breakdown or breakthrough.

So, what’s the path forward? Is it time for a new kind of resource for this overlooked parenting stage?

Understanding the Dynamics

1. PDA (Pathological Demand Avoidance) in Young Adults

PDA is often misread as oppositional behaviour. But beneath the surface is intense anxiety and a deep need to retain control. For parents, especially those with ADHD, navigating this can be particularly hard because:

• PDA resists structure.
• ADHD struggles to create or maintain structure.
• The result? Chaos, conflict, and shame.

2. RSD (Rejection Sensitive Dysphoria) and Stonewalling

Young adults with RSD can perceive criticism or requests as painful rejection. They may shut down or lash out. Stonewalling—a refusal to speak, engage, or acknowledge—is often a protective behaviour. However, to a parent, especially one with ADHD emotional reactivity, it can feel like abandonment or attack.

3. Substance Use as Emotional Escape

Some neurodivergent young adults use alcohol or cannabis to numb their anxiety, sensory overload, or social pain. Parents may feel helpless, unsure if this is “normal experimentation” or a deeper coping mechanism.

4. Parental Role Conflict

• Mother may feel overwhelmed, emotionally reactive, guilty, or confused. Her ADHD may make it harder to stay calm or remember strategies.
• Father may see his role as protecting the family and believes a line needs to be drawn. He considers the daughter’s behaviour as controlling or even emotionally abusive.
• Younger siblings may walk on eggshells, absorb tension, or model unhealthy behaviour.

What Would a Therapist Suggest?

A skilled family therapist might recommend the following steps:

1. Separate the Behaviours from the Identity

Frame your daughter’s behaviour (stonewalling, withdrawal, resistance) as symptoms of distress, not personality defects. This will soften parental reactivity and open space for a compassion-based strategy.

2. Create a Parallel Process of Support

Instead of trying to fix the young adult, a therapist may recommend:

• Mother gets ADHD-informed emotional coaching or therapy
• Father joins parallel sessions to explore boundaries vs. enmeshment
• Parents meet together to create a parenting agreement or exit strategy
• Siblings are supported to voice their needs and fears

3. Implement “Loving Boundaries” Framework

• Outline what is okay and what is not OK in the home (e.g., alcohol, aggression, avoidance of all household responsibilities)
• Communicate these with clarity, not punishment.
• Provide choices with consequences (“We want you here, but if X continues, Y will change.”)

4. Address Readiness for Supported Exit

A therapist may help assess whether the daughter is ready to leave, perhaps with support. Options may include:

• Shared housing with a mentor or friend
• A supported living arrangement
• A slow transition with skill-building benchmarks
• Social services consultation if self-neglect is an issue

5. Use Indirect Communication Tools

With stonewalling, confrontation often fails. Try:

• Handwritten notes
• Voice recordings
• Text messages followed by space
• Nonverbal affirmation and permission to process

So What’s the Way Forward?

The family must shift from reacting to the behaviour to responding to the system. That includes:

• Validating the mother’s ADHD experience and challenges
• Supporting the father’s instinct to protect, without pathologising the daughter
• Creating a family-centred plan that doesn’t hinge on immediate change from the young adult
• Download your FREE Circle of Support Sheet here 

Final Thought

You are not a failure. You are parenting in a situation with few roadmaps and high stakes.

The way forward is neither rejection nor rescue—but a third way: compassionate boundaries, support for everyone, and long-term thinking.

If this sounds like your family, you’re not alone—and more help is coming.

For further research from leading professionals in the field, check out my recommended reading section.

Wondering what to read next, why not try The Cost of Camouflage: Understanding Masking in Neurodivergent Clients